HW11 Composer: Gym machine rental

Create a Business Network Archive (BNA) with the appropriate models, transactions, and access constraints that fulfill the requirements below. The BNA must have an initial transaction (setupHomework) that sets up a ledger state, where the fulfillment of each requirement can be demonstrated (assuming that the ledger is empty before the call of the initial transaction). Transactions that would dynamically add participants or assets are not needed, unless noted explicitly under the requirements, except the initializer transaction.

Please test your solution on Composer Playground before submission.

For every Participant and Asset type, the unique identifier must be a non-optional String field with the name id. The value of the field must conform to the following format: <TYPENAME>_<COUNTER>. For example, if we have a Participant type named User, then the id of the first created user must be USER_0, the id of the second user must be USER_1, etc.

Problem statement

Implement a BNA for gym machine rental.

• There should be at least two participant types: Gym and Member.
• Each Member has a name (non-unique), an account balance and a Gym associated.
• Each Gym has a name, an account balance, and some associated machines.
• Machines have names and three different price values (morning, afternoon, evening).
• Each Member can:
  • rent a machine if it wasn't marked as rented in the last half an hour, which:
    • transfers the appropriate price from the user's account balance to the machine's gym,
    • marks the machine as rented for half an hour.
  • add money to his balance.
• Gyms can add machines, given that they provide their name and price values.

Additional requirements:

• The initializer transaction should set up a gym with 1 machine and at least 2 users.
• Transactions that create users or create gyms are not required.
• Implementation of renting for specified times is not necessary; the transaction uses the current time to mark the machine as rented.
• Negative balances are not possible, transactions that'd create such a state should be rejected.

Example scenario

Alice and Bob live near "Claire's Gym," which has a single treadmill, with prices 2-3-5. Alice has an account balance of 10 units. Alice rents the machine during the afternoon for 3 units. Bob tries to do the same, but the transaction fails.

Transactions

• addMoney
• addMachine
• rentMachine